我爱上了异步和等待,但我不知道如何等待一个文件,而无需使用Task.Run开放。似乎是在WRT 。哪里是.NET 4.5相同呢?我问,因为如果我在远程机器上访问UNC共享这有阻止了很长的时间,如果机器被关闭或不响应由于某种原因,网络请求的潜力。这似乎是这么大了点。
使用(的FileStream流=等待Task.Run(()=>新建的FileStream(@C:\ TEMP \的text.txt,FileMode.OpenOrCreate,FileAccess.Read, FileShare.Read,4096,真正的)))
{
byte []的bytesToRead =新的字节[stream.Length]
等待stream.ReadAsync(bytesToRead,0,bytesToRead.Length).ConfigureAwait(假);
返回bytesToRead;
}
解决方案
不幸的是,即使文件打开是异步的,在设备驱动程序级别,有一个异步打开文件没有的Win32 API。所以这就是为什么没有.NET同等学历;我不知道是肯定的,但我怀疑的WinRT API由它排队到线程池伪造异步操作。
所以,最好的办法是做一个类似的解决方法:使用 Task.Run
。我想换行所有的的FileStream
code。在 Task.Run
,虽然。
I'm falling in love with async and await, however I cannot figure out how to await a file open without using Task.Run. There seems to be an API in WRT. Where is the .NET 4.5 equivalent? I ask because if i'm accessing a UNC share on a remote machine this has the potential to block for a very long time if the machine is down or not responding to network requests for some reason. It seems like such a big over site.
using (FileStream stream = await Task.Run(() => new FileStream(@"c:\temp\text.txt", FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read, 4096, true)))
{
byte[] bytesToRead = new byte[stream.Length];
await stream.ReadAsync(bytesToRead, 0, bytesToRead.Length).ConfigureAwait(false);
return bytesToRead;
}
解决方案
Unfortunately, even though file opens are asynchronous at the device driver level, there is no Win32 API for an asynchronous file open. So that's why there's no .NET equivalent; I don't know for sure but I suspect that the WinRT API is faking an asynchronous operation by queueing it to the thread pool.
So, the best solution is to do a similar workaround: use Task.Run
. I'd wrap all the FileStream
code in Task.Run
, though.
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